Respiratory apparatus



l,472,l l T Oct. 30 1923.

A. B. DRGER RESPIRATORY APPARATUS Filed. June 9. 1921 l I l I 1 l l l 1 l 1 l I l 1 l l l 1 1 1 1 u 1 lill/[11111111111111171111111 Patented @et 36, 1923.

errno rss ALEXANDER BERNHARD DRGER, OF LBECK, GERIVANY.

RESPIRATORY APPARATUS.

Application filed June 9, 1921.

To all whom t may concern.'

Be it known that I, ALEXANDER BERNHARD DRGER, a citizen of Germany, residing at Lubeck, Germany7 have invented certain new and useful Improvements in Respiratory Apparatus, of which the following is a specification.

rlhis invention relates to that type of respiratory apparatus which include a breathing bag and a reservoir adapted to be heated for gasifying liqueiied gas, such as liquid air, liquid oxygen or a mixture of liquid oxygen and nitrogen, to support respiration and in which the vaporiZatio-n of the gas is accomplished by the heat of the surrounding external atmosphere in contradistinction to that type of apparatus in which the heat of the exhaled air is utilized for the same purpose. In the known appliances of the type to which the present invention hasv reference the vaporization is edected by the direct heating eifect of the surrounding atmosphere or by affording the external atmosphere an opportunity to flow through al heating pipe which surrounds or passes through the reservoir containing the liquid', in order to lgive up its heat to this latter.l The extent of the vaporization in the latter type of apparatus referred to depends upon the volume and the velocity of the external air which flows through the heating pipe and which is unequally warm owing to the natural equilization of weight.` In order to enable the vaporization of the r liquid gas provided to supportrespiration in suchy apparatus to be determined and controlled, the heating pipe is caused to communicate with the outer air by adjustable openings in the form of stop cocks or the like. By opening the heating pipe more or less, more or less of the outer air is allowed to flow through so that the volume of the liquci'ied gas which is to be vaporiZe-d to support respiration can be suitably regulated by suitable adjustment of the cocks on the heating pipe to correspond to the respiratory' requirements of themoment. The inu creased or diminished requirements of respiration of the ,wearer of the apparatus can beV therefore accommodated only by a strict and continuous control of theheating pipe and ofthe volume of the outer air flowing through it. Such an adjustable vaporization of the liquid gas for supporting respiration bythe heat ofthe outer air is Serial No. 476,235.

however troublesome and inconvenient and not always reliable.

The object of the present invention is to provide an apparatus in which these disadvantages and objections are overcome and in which the vaporization of the liquid gas for supporting respiration is automatically effec-ted' and controlled by the operation of breathing itself; that is to say the suction and force movements of the breathing bag belonging to the apparatus (i, ea the defiation and inflation thereof) are used to bring the required outer air into contact with the reservoir containing the liquid and to drive it through its heating pipe, so that the supply of air and consequently the extent of the vaporization depends upon the depth and frequency of the periods of respiration and is automatically regulated at all times according to the respiratory requirements ofthe wearer of the apparatus.

The course of Ithe outer air controlled by the breathing bag can in this apparatus be so determined, by the aid of suction and force valves which conveniently communicate with the heating pipe that the outer air is compelled to always flow through the heating pipe in one direction. With this arrangement the breathing bag is only brought into contact with the comparatively warm outer air and not with the air which is cooled down by the reservoir for the liquid, and therefore does not become hardened or otherwise damaged.

The heatingup of that portion of the outer air which serves as the heating` agent may also be effected by making use of the heat produced by the respired air particularly through. the carbonio acid absorption in the air purifying charge of the cartridge or absorber connected with the apparatus. For this purpose the structure of the api'mratus is so arranged that the 'charge gives up its radiant heat to the outer ail` which is set in motion by the breathing bag and acts as heating air.

In the accompanying drawing:

Figure l is an elevation, partly in section of a constructional example of a respiratory apparatus embodying this invention.

Figure 2 is a similar view showing a modified constructional'form.

Figures 3 and l are similar `views of two further constructional forms of the respiratory apparatus. Y

The liquefied gas, for example, liquid oxygen orsuppert-ingrespiration is centained .in

' a reservoir-@1(see Figure l) ot'aikind suitable for the purpose and filled With a convenient insulating composition al such as asbestos or the like. Well known Way in an eXternal-i-eceptaele which protects it from the effects ot'the outer air. In the receptaele-r-b is'also-placed-f the breathing bag c of the respiratory apparatusavhiclrmaybe yof any-usualorm `and" is yconnected in the Well-known Way with an air.` pu'rifyiiigf.cartridge 'or' absorber al.' a valve' chest -e (provided: with an `inhalation vali/'e e1 and an eXhal'ation valve/e2 and a' breathingpipe ,t leading-to thepart of the apparatus-5 actingas intermediary-.to the breathing` organs-1 that? is tosay, tothe mouthpiece r (Figure l) or thefniaslr.- s' (Figure 2)'.V Frornithereservoir co5 a-pipe f/fleadsfto the1 valve chest 6, in orderto conve the Yva Jorizedfli uid wasl 1Cor-fv su 'i4 .y 23 7 i by4 fulll lines? thereinand thereby exerts vasuction'aetio-n inthe-'outer receptacle b which d aws external air in-throughthe apcrtured bossvh located-in=the-ivall-of the receptacle/Z). When' the `Wearcln exhailes; the b-reatl'iingl bag 0 again becomes y inflated and expels the air=`previonsly drawn'inte the receptacle b out througl'r the apertured boss 71,; This op eration isfofcourse repeated.. *The suction and pressure movementsv of the breathing bag-rinthe receptacle cause the outer air which iis-'drawn inand expelled again to li'ov' through theinteunediate' spaces existwr ing;` betweentlie reservoir a for the liquid andthe receptacle 7) and constituting. heat! ing passagesi The air may also be causedfto pass 'through aspeeialheating pipe z' which traverses*the'I reservoir a asshown' in: the dra-Wing, said* air bein'gfadinittedfin one di reeti'onand expelled inl another and giving-1 Y up l'its' heat to the reservoir aanditsoontents vas it? passesthrouglrthe apparatus. The-'liep' uidE Vaporized thereby passes-throguhl-thcijiipe :g5 into the 'respiratory apparatus.: The

i. strongerythat-visfto'say, thesdeeper'and morey 'frequent the` breathingof the wearer of the apparatus.: the"v more the outer0 air:l isv moved' to and l'ro in the receptacle b'aiidthemore gas te support respiration. will beY generated froinitheliquid--in the? reservoir a. Thefsupply "of 'gasto the -v apparatusfffor supporting respirationV is therefore autornatically-` regir'` lated` byf the act of breathing itself.

' Y Iny many easesit-Will be` foundnoonvenient to# arrange@ theA reservoir a l for?v theH liquid `651 andf'fthebreathing'v` baglcv ea'elr in .awsegai'fa-teenclosing receptacle b1 andV b2 respestit-fely;`

(see Fig. and to connect the receptacles byapassage ofor'the like?. Y j

lffit vis desired to prevent-tlief breathing bag from, becoming hardened by Contact y .n y Y with the air which has been cooled down by This*reservoir'1s"locatedintheA fin one dir Vction onlyby means of non-return-valVes-areund or through the reservoir a. For this purpose the enclosing receptacle b (see Figuresandre) and?)2 (Figure V3') i sf provided: with: an` inletseche-ti 1 m Whi ch latter' isf furnished fw-ith' a suction Valve n arranged? to 'open automatically" Whenvthe weairen inhales (dellartion: of thefbrea-thingc; bag) Whilet-he so elr'etv '71"Whichnow" merely serves as an outlet is fitted Witha pressure. valve o" (see 1{Figuiis'' 2? anche) f Whiehz opens automatically i when the:- wearer eirhalesv (insv liatioin ofvvv breath-ingyb ag); y i Figurel shows thatl such' a.: pressure it y lvefolinsteadf? ofV bei n g arranged? in 'thef outletssoclret*l h ofthe reeeptaele b1 which: surrounds the rese-rif'foin` a, :lor-"the liquidwinayv `also be anrangecl` inst-he passage or connectingbraneh L:

In thencenstructiona ieX-ampleseshown i1 Figures 21and-1l vduring-the*suetien-period- Y of the breathingfba'g; extern alcair :isf drawn into the receptacle@ through tlieautematfieal 1y; opening? Valter/11,; Whilst the valve` 0= ref mains'- closed.y The outen ain thus-drawn into the-receptacle Z);asthe*breathing bag'. .is

derlatedis*expelled 'againvby thewnext sub sequent i'nliation= of the` breathing#- bag-5 through thef'valve -o w-hiehopens automatiseally; WhilstV the' Valve*y wf reinains` closed: During; the expelling movementnthe'ainllews around-V the' reservoirM m for the liquid: on througlr the'A heating, pipe: 'z' -ther'eotf rei speeti'yely.'V Y v In the construetional .example shoWn-4 in.V Figure' the fouten air' `which VisdrawnPinto' thereoeptaclebg'bythesuetionY stroke or the breathingbag" is forced.; over by themerit pressure'V` stroke` through the kpressure valve 0 into thev reservoin `721i and# heat'- ing: pipe respectively,Where Vit teinporarily remains; the"transfe`rred airfdoes not passfout throughtheunobstrueted Socket strokef oil" the breathing bag; Y takesi place whenv it isfeXpell'edby the new: elargge.ir ofi o liter airY drawn; Yi ni the? aetfieir of f thetjhreath' ing;A and-- 'so en nytlie '31 )amen 'Thisf-isvdone inwsuch afway that the-`lewf always: takes fp lee 'inthesanie-direetieniand; cooledfairdeesenocome einteffeentaetwitlr the breathinLgbag;A Isnethei apparati1'sslreiffir Y showin inf Figures .2 to 'all the breathing :bafgi there-- Y in Figure l the breathing bag, on the contrary, acts in the same manner as the piston of a syringe in that it expels the air drawn in through the socket 7i into the receptacle 7J through the same opening again; the heating air thus 'has a to and Jfro movement imparted to it around or through the res` ervoir for the liquid, the air cooled down on the inward movement by contact With the reservoir a passing over the breathing bag which is avoided in the. apparatus accord ing to Figures 2 to 4.

Figure 4 shows the manner in which the heating of the chemical charge of the absorber Z by the exhaled air or by the heat developed by the absorption of the carbonio acid respectively can be utilized to Warm up the outer air Which is to serve for the heating of the reservoir containing theliquid. This is effected by locating the absorber Z simply in the receptacle Z) (or b2 in Figure 2) or by arranging it in suiciently close proximity to the receptacle, so that the heat developed by the charge of t-he absorber and radiating from it warms up the air in the receptacle.

In order to avoid over-inflation of the breathing bag With gasto support respiration resulting from excessive vaporization, it is advisable toy provide the breathing bag With an outlet fitted with a non-return valve through which the amount of gas in excess of the requirements can escape. An outlet of this kind provided With a nonreturn valve p is shown in Figure l.

I claim:

l. In a respiratory apparatus of the class described the combination of a reservoir containing liquefied breathing gas to be heated and vaporized by external air to support respiration, containing means enclosing the said reservoir as an air heating jacket and being in communication with the atmosphere, and a breathing bag arranged Within the said containing means to automatically regulate7 according to its pulsations, the external air supply to the said heating jacket.

2. In a respiratory apparatus of the class described the combination oi' a reservoir containing liquefied breathing gas, a breathing bag, and containing means enclosing the reservoir and the breathing bag and being provided with an air inlet furnished with an inhalation valvej and with an air passage provided With an exhalation valve whereby the flow of air through the apparatus is always in the same direction.

3. In a respiratory apparatus of the class described the combination oi' a reservoir containing liquefied breathing gas, a breathing bag, a receptacle containing the reservoir and the breathing bag and being provided With means whereby a supply of external air is passed to and from the said receptacle7 and an air purifying cartridge for the exhaled air located in the receptacle in close proximity to the breathing bag.

ALEXANDER BERNHARD DRGER. 

